Preparation, crystallographic, and infrared properties of some actinide tetrahalide–phosphine oxide complexes

Abstract

Protactinium, neptunium, and plutonium tetrahalide–phosphine oxide complexes of the type MX₄,2L [M = Pa, Np, and Pu; X = Cl and Br; L = Ph₃PO and (NMe₂)₃PO] have been prepared by reactions in nonaqueous solvents. Thorium tetrabromide forms a 1:3 complex with triphenylphosphine oxide. Some chemical properties and X-ray powder diffraction results are reported together with i.r. spectral results (4000–33 cm.^–1) for these and some previously known uranium tetrahalide–phosphine oxide complexes. The assignment of metal–oxygen and metal–halogen stretching vibrations is discussed.